1. Field of the Invention
This invention relates generally to the field of frequency and phase lock detectors. More particularly, this invention relates to an improved frequency and phase lock detector which does not produce false lock indications when there is no signal present.
2. Background of the Invention
When electronic circuits are used to indicate when two signals are essentially identical, a false indication is often obtained when there is in fact no signal present. In this instance, although the two signals are technically identical, the indicating circuit would lead one to believe that two signals are present and locked. The present invention addresses this problem by providing an improved circuit to indicate when two signals are identical in phase and frequency without providing a false indication that they are identical in phase and frequency when there is no signal present.